I've been having this problem for a while now and I have no clue as to what the cause could be.

Basically the voltage on the PCIE +3.3V wire on the 24pin connector drops significantly over time. From 3.295V to <3.15V which causes the system to shut down. The wire gets a bit warm too leading me to think it's a connection problem but the connector looks just fine and it does this on multiple PSU's.

It's just this one wire too, the other 3.3V wires on the 24pin all output the proper 3.295V.

All the 3.3V wires read the same 326 Ohms, I measured with the 24pin plugged in and without it but it made no difference.